Action points are used in the V.A.T.S. system to attack opponents, each weapon has it own cost per use and can be found on the weapons page. Unlike in the turn-based games, action points in Fallout 3 and Fallout: New Vegas are not accumulated at the end of a turn. Instead, Action Points are regenerated over time.

The maximum figure achievable without chems is 148.
Starting AP = 65 + 10 Agility (85) + the Action Boy perk at level 16 (110) + Ledoux's hockey mask (135) + the tribal power armor (148). The +15AP bonus is negated by the -1 Agility penalty which the armor carries. An alternative to negate the -1 Agility is to use the Chinese stealth armor multiple hat glitch/exploit to wear Poplar's hood which has a +1 Agility bonus and stack it with Ledoux's mask for the +30 AP, making the maximum total 150 AP.

A character will take 16.66 seconds to recover their AP bar to full regardless of their AP total, unless their AP is modified by perks. It should be noted that AP gained through perks do NOT count towards regeneration rate. Therefore a player character with 115 AP, 30 of which were gained through Action Boy perks, would actually take over 23 seconds to fully recover their AP bar. Furthermore, the perk Nerves of Steel decreases this regeneration period by 20%, to a potential minimum recovery period of 13.33 seconds.

The exact recovery time can be derived from the GECK variable Action Points Restore Rate, which in Fallout: New Vegas is the inverse of the number of seconds required to fully restore the AP bar. The default value is 0.060 (1/0.06 = 16.66 seconds).